If you are have issues getting Asp.net 2.0 membership and personalization running under Vista then you are not alone: there seems to be security issues dynamically creating the database.
Luckily the workaround is pretty straight forward, all you have to do is:
1. Install SQL Server 2005 Developer edition
2. Create a Database
3. Run the ASPNET_REGSQL utlity
4. Tell ASP.NET 2.0 to use this database with